The present invention relates generally to a process and apparatus for effecting sterilization of objects and, more particularly, to a process and apparatus for effecting sterilization through the utilization of hydroxide peroxide and ultraviolet energy.
In the field of sterilization, liquid hydrogen peroxide has been used effectively as a bactericide. There are numerous applications of liquid hydrogen peroxide for accomplishing sterilization and disinfection purposes. One is described in British Pat. No. 1,513,266, in which hydrogen peroxide (H.sub.2 O.sub.2) with steam are mixed together, and the resulting mixture is condensed on the inner wall of an enclosure. The condensate is eventually evacuated, the enclosure is dried and sterilization is thereby achieved. Another approach is described in U.S. Pat. No. 4,366,125, which discloses using an atmospheric mist or fog of liquid phase hydrogen peroxide and followed by irradiation with ultraviolet energy. Still another sterilization approach is to utilize gaseous phase hydrogen peroxide. Gaseous phase hydrogen peroxide is an effective sterilant which is employed for use in sterilizing objects. Examples of such prior art approaches are described adequately in U.S. Pat. Nos. 4,169,123 and 4,169,124. Basically, in such a procedure, hydrogen peroxide vapor is used for sterilization purposes and is achieved by vaporizing, in a closed sterilization chamber, a relatively dilute liquid solution of hydrogen peroxide and water. The vapors so produced contact the items to be sterilized. This technique is generally referred to as cold gas sterilization as opposed to a heat or liquid contact sterilization. Vaporous hydrogen peroxide because of its low toxicity is desireable since it provides a safe alternate for sterilizing hard surfaces.
It is also known to use ultraviolet energy provided by a ultraviolet lamp for purposes of effecting sterilization of various types of articles. Generally, relatively long sterilization times are required when using ultraviolet energy. One known approach, described in an article entitled, "The Combined Effect of Hydrogen Peroxide and Ultraviolet Irradiation on Bacterial Spores", appearing in Journal of Applied Bacteriology, Vol. 47, 263-269, 1979, and has described combining hydrogen peroxide with ultraviolet energy. However, in this latter approach, the hydrogen peroxide utilized was in a liquid phase. Also, U.S. Pat. No. 4,366,125 describes utilization of ultraviolet radiation with an atmospheric mist or fog of finely divided hydrogen peroxide liquid, but at separate times.